Automotive bodies, home electric appliances and the like have been manufactured with metal materials such as steel sheets, galvanized steel sheets, and aluminum alloys. In general, after subjecting to a chemical conversion treatment step as a pretreatment, a treatment such as coating is carried out. As the chemical conversion treatment, a treatment using phosphate is generally carried out. In the chemical conversion treatment with phosphate, a surface conditioning treatment is generally carried out as a pretreatment for allowing fine and compact phosphate crystals to be deposited on the metal materiel surface.
Examples of known surface conditioning compositions for use in such a surface conditioning treatment include treatment liquids containing titanium phosphate particles referred to as a Jernstedt salt, or bivalent or trivalent metal phosphate particles.
For example, a surface conditioning composition is disclosed which includes phosphate particles of at least one kind of bivalent or trivalent metals having a particle diameter of 5 μm or less, and an alkali metal salt or ammonium salt, or a mixture thereof, and which has a pH adjusted to be 4 to 13 (for example, see Patent Document 1).
Also, a surface conditioning composition is disclosed which includes at least one kind of phosphate particles selected from phosphate particles including one or more kind(s) of bivalent and/or trivalent metals, and a variety of accelerator (for example, see Patent Document 2).    [Patent Document 1] Japanese Unexamined Patent Application, First Publication No. Hei 10-245685    [Patent Document 2] Japanese Unexamined Patent Application, First Publication No. 2000-96256